A new individually designed 3D printing guide plate-assisted internal fixator (INFIX) surgery for the treatment of pelvic fractures

Abstract

Objectives: This study aimed to evaluate the effectiveness of 3D-printed guide plate-assisted descending INFIX technology in the management of unstable pelvic ring injuries.

Methods: This retrospective study analyzed the clinical data of 51 patients who underwent INFIX surgery for pelvic ring fractures at the Second Hospital of Shanxi Medical University between January 2023 and December 2024. Based on the use of 3D-printed guide plates, the patients were divided into two groups: conventional group (n = 28) and guide plate group (n = 23). The surgical parameters, including operative time, number of intraoperative fluoroscopic evaluations, intraoperative blood loss, and incision length, were recorded and compared between the two groups. The postoperative reduction accuracy was evaluated using the Matta imaging scoring system, while the Majeed scoring system was used to obtain functional outcomes in clinical follow-up. All the potential complications were identified and evaluated accordingly.

Results: Both the patient groups were followed up for a period of 6–11 months, with an average of 8 months. The guide plate group demonstrated shorter surgery duration, fewer fluoroscopic assessments, and fewer guide needle trajectory adjustments compared to the conventional group (P < 0.05). The guide plate group exhibited a higher percentage of good Matta scores than the conventional group (17.39% vs. 14.29%).

Conclusions: The individualized 3D-printed navigation template significantly reduced the complexity of INFIX surgery, minimized intraoperative and postoperative complications, and enhanced clinical outcomes. The procedure can be safely performed in resource-limited medical facilities, making it feasible for junior surgeons with limited pelvic anatomy experience.

Keywords: 3D print; Anterior ring injury; INFIX; Internal fixation; Pelvic fracture.

Fig. 1

Design of the Navigation Template and 3D Pelvic Model. (a) A 2 mm cylinder was positioned at the center of the teardrop region to construct a virtual screw insertion channel. (b) Lateral view of the virtual screw channel within the three-dimensional pelvic model (c) Navigation template and hollow guide tube were designed based on the central channel of the teardrop region. The template base was secured to the bone groove between the anterior superior iliac spine and the anterior inferior iliac spine, with a 2.5 mm positioning Kirschner pin channel constructed adjacent to the base. (d) Lateral view of the 3D-printed navigation template and the three-dimensional pelvic model, demonstrating preoperative surgical simulation

Fig. 2

How navigation templates operate in the infix operation mode. (a) reveals the grooves between the anterior superior iliac spine and the anterior inferior iliac spine and removes the supracossicular soft tissue. (b) Placing the guide between the grooves and inserting a temporary Kirschner needle to give fixation. (c) Driving a positioning Kirschner needle. (d) Fluoroscopy after removal of the guide plate and temporary Kirschner needle, with the guide needle in the center of the “tear drop position”